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    <title>Document</title>
    <script>
        var month=prompt("请输入月份（1-12）");
        var numbernum=Number.parseInt(month);
        console.log(typeof month);
        console.log(typeof numbernum);
        switch(month){
            case "1":
                console.log("一月");
                break;
            case "2":
                console.log("二月");
                break;
            case "3":
                console.log("三月");
                break;
            case "4":
                console.log("四月");
                break;
            case "5":
                console.log("五月");
                break;
            case "6":
                console.log("六月");
                break;
            case "7":
                console.log("七月");
                break;
            case "8":
                console.log("八月");
                break;
            case "9":
                console.log("九月");
                break;
            case "10":
                console.log("十月");
                break;
            case "11":
                console.log("十一月");
                break;
            case "12":
                console.log("十二月");
                break;
            default:
                console.log("输入错误，请输入1-12之间的数字。");
        }
        if(null){
            console.log("这是一个真值");
        } else {
            console.log("这是一个假值");
        }
    </script>
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<body>
    
</body>
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